CN114982305A

CN114982305A - Techniques for timing advance grouping for each subset of synchronization signal blocks in a wireless communication system

Info

Publication number: CN114982305A
Application number: CN202080093628.4A
Authority: CN
Inventors: 张倩; 周彦; 骆涛
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2020-01-24
Filing date: 2020-12-16
Publication date: 2022-08-30
Anticipated expiration: 2040-12-16
Also published as: CN114982305B; US11943725B2; WO2021150326A1; US20210235397A1; EP4094499A1

Abstract

Aspects described herein relate to: identifying a Timing Advance Group (TAG) for a second Remote Radio Head (RRH) different from the first RRH, the TAG associated with a Timing Advance (TA) offset, the first RRH and the second RRH associated with a serving cell; switching from the first RRH to a second RRH in accordance with the TAG and associated TA offset; and transmitting data to the second RRH on the uplink communication channel.

Description

Techniques for timing advance grouping for each subset of synchronization signal blocks in a wireless communication system

Cross Reference to Related Applications

The present application claims the benefit of the following applications: U.S. provisional application sequence No.62/965,699, entitled "TECHNIQUES FOR TIMING ADVANCE GROUP PER SUBSET OF SYNCHNIZATION SIGNAL BLOCKS IN A WIRELESS COMMUNICATION SYSTEM", filed 24.1.2020; and U.S. patent application No.17/122,780, entitled "TECHNIQUES FOR TIMING ADVANCE GROUP PER SUBSET OF SYNCHNIZATION SIGNAL BLOCKS IN A WIRELESS COMMUNICATION SYSTEM", filed on 15.12.2020, which is hereby expressly incorporated by reference in its entirety.

Technical Field

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to providing cell mobility based on a Timing Advance Group (TAG) of each Synchronization Signal Block (SSB) subset.

Background

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems, and single carrier frequency division multiple access (SC-FDMA) systems.

These multiple access techniques have been employed in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate on a city, country, region, or even global level. For example, fifth generation (5G) wireless communication technologies (which may be referred to as NRs) are envisioned to extend and support a wide variety of usage scenarios and applications with respect to the generations of current mobile networks. In one aspect, the 5G communication technology may include: enhanced mobile broadband that addresses human-centric use cases for accessing multimedia content, services, and data; ultra-reliable low-latency communications (URLLC) with certain specifications for latency and reliability; and large-scale machine-type communications that may allow for a very large number of connected devices and the transmission of relatively low amounts of non-delay sensitive information.

For example, some implementations may improve transmission speed and flexibility for various communication technologies (such as, but not limited to, NR), but may also increase transmission complexity. Accordingly, improvements in wireless communication operations may be desirable.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

An example implementation includes a method of wireless communication at a User Equipment (UE), comprising: identifying a Timing Advance Group (TAG) for a second Remote Radio Head (RRH) different from a first RRH, the TAG associated with a Timing Advance (TA) offset, the first RRH and the second RRH associated with a serving cell. The method further comprises the following steps: switching from the first RRH to the second RRH in accordance with the TAG and associated TA offset. The method further comprises the following steps: transmitting data to the second RRH on an uplink communication channel.

Further example implementations include an apparatus for wireless communication comprising a memory and at least one processor in communication with the memory. The at least one processor may be configured to: identifying a TAG for a second RRH different from the first RRH, the TAG associated with a TA offset, the first RRH and the second RRH associated with a serving cell. The at least one processor may be further configured to: switching from the first RRH to the second RRH in accordance with the TAG and associated TA offset. The at least one processor may be further configured to: transmitting data to the second RRH on an uplink communication channel.

Additional example implementations include an apparatus for wireless communication. The apparatus may include: means for identifying a TAG for a second RRH different from a first RRH, the TAG associated with a TA offset, the first RRH and the second RRH associated with a serving cell. The device further comprises: means for switching from the first RRH to the second RRH in accordance with the TAG and associated TA offset. The device further comprises: means for transmitting data to the second RRH on an uplink communication channel.

Further example implementations include a computer-readable medium storing computer code executable by a processor for wireless communication at a network entity, the computer code comprising code to: identifying a TAG for a second RRH different from the first RRH, the TAG associated with a TA offset, and the first RRH and the second RRH associated with a serving cell; switching from the first RRH to the second RRH in accordance with the TAG and associated TA offset; and transmitting data to the second RRH on an uplink communication channel.

In some implementations, switching from the first RRH to the second RRH at a cell may include: communicating with the cell using the beam of the second RRH instead of the beam of the first RRH.

In some implementations, the first RRH can be associated with a different TAG and associated TA offset, the different TAG being different from the TAG associated with the TA offset of the second RRH.

In some implementations, the first RRH can be associated with a first subset of RSs and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs can be associated with the TAG and the first subset of RSs is associated with a different TAG.

In some implementations, switching from the first RRH to the second RRH can include: switching from a first set of beams associated with the first RRH to a second set of beams associated with the second RRH, the second set of beams being quasi-co-located with the second RS subset of the TAGs.

In some implementations, the method may further include: receiving DCI or a MAC CE on a downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

In some implementations, the method may further include: performing uplink TA measurements for both the first RRH and the second RRH; and updating the TAG and TA offset of the second RRH and the different TAG and TA offset of the first RRH.

In some implementations, the TAG for the second RRH can correspond to a most recently received TAG for the second RRH.

In some implementations, the data may be sent on the uplink communication channel based on the most recently received TAG for the second RRH.

In some implementations, the RS may correspond to at least one of an SSB reference signal, a channel state information reference signal, or a positioning reference signal.

In some implementations, the method may further include: receiving a DCI or a MAC CE indicating one or both of a plurality of cells or a plurality of PCIs, the plurality of cells or the plurality of PCIs being associated with one or both of a serving cell or a non-serving cell.

One example implementation includes a method of wireless communication at a serving cell having a first RRH and a second RRH. The method comprises the following steps: transmitting the first TAG and associated TA offset for the second RRH to the UE on a downlink communication channel. The method further comprises the following steps: detecting a handover of the UE from the first RRH to the second RRH. The method further comprises the following steps: receiving data from the second RRH on an uplink communication channel.

Further example implementations include an apparatus for wireless communication having a first RRH and a second RRH, comprising a memory and at least one processor in communication with the memory. The at least one processor may be configured to: transmitting the first TAG and associated TA offset for the second RRH to the UE on a downlink communication channel. The at least one processor may be configured to: detecting a handover of the UE from the first RRH to the second RRH. The at least one processor may be configured to: receiving data from the second RRH on an uplink communication channel.

Additional example implementations include an apparatus for wireless communication having a first RRH and a second RRH. The apparatus may include: means for transmitting the first TAG and associated TA offset for the second RRH to the UE on a downlink communication channel. The device further comprises: means for detecting a handover of the UE from the first RRH to the second RRH. The device further comprises: means for receiving data from the second RRH on an uplink communication channel.

Further example implementations include a computer-readable medium storing computer code executable by a processor for wireless communication at a network entity, the computer code comprising code to: transmitting a first TAG and associated TA offset for the second RRH to the UE on a downlink communication channel; detecting a handover of the UE from the first RRH to the second RRH; and receiving data from the second RRH on an uplink communication channel.

In some implementations, the method may further include: sending a second TAG and associated TA offset for the second RRH to the UE after transmission of the first TAG.

In some implementations, detecting the handover from the first RRH to the second RRH can include: detecting the handover as a function of the second TAG and associated TA offset for the second RRH, the second TAG and associated TA offset corresponding to a nearest TAG.

In some implementations, the first RRH can be associated with a first subset of RSs and the second RRH can be associated with a second subset of RSs, and wherein the second subset of RSs is associated with the TAG and the first subset of RSs is associated with the different TAG.

In some implementations, the method may include: transmitting DCI or a MAC CE on the downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

In some implementations, the method may include: transmitting a DCI or MAC CE indicating one or both of a plurality of cells or a plurality of PCIs, the plurality of cells or the plurality of PCIs being associated with one or both of a serving cell or a non-serving cell.

To the accomplishment of the foregoing and related ends, one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed and the description is intended to include all such aspects and their equivalents.

Drawings

The disclosed aspects will hereinafter be described in conjunction with the appended drawings, provided to illustrate and not to limit the disclosed aspects, wherein like designations denote like elements, and in which:

fig. 1 illustrates an example of a wireless communication system in accordance with various aspects of the present disclosure;

fig. 2 is a block diagram illustrating an example of a network entity (also referred to as a base station) in accordance with various aspects of the present disclosure;

fig. 3 is a block diagram illustrating an example of a User Equipment (UE) in accordance with various aspects of the present disclosure;

fig. 4 is a flow diagram of a method of wireless communication at a UE (and more particularly, a method of intra-UE cell mobility based on a Timing Advance Group (TAG) per Synchronization Signal Block (SSB) subset);

fig. 5 is a flow diagram of a method of wireless communication at a network entity (and more particularly, a flow diagram of network supported intra-cell mobility based on TAGs for each SSB subset); and

fig. 6 is a block diagram illustrating an example of a MIMO communication system including a base station and a UE in accordance with various aspects of the present disclosure.

Detailed Description

Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details.

In summary, the described features relate to the reporting of timing differences for different Synchronization Signal Blocks (SSB) in a fifth generation new radio (5G NR). For example, multi-beam operation may be enhanced by targeting frequency range 2(FR2), while also being applicable to FR 1. In one example, these enhancements may include identifying and specifying features to facilitate more efficient (lower latency and overhead) downlink or uplink (DL/UL) beam management to support higher intra-layer 1 or layer 2(L1/L2) and L1/L2 centric inter-cell mobility and/or a greater number of configured Transmission Configuration Indicator (TCI) states. This example may include a common beam for data and control transmission/reception for DL and UL, in particular for in-band Carrier Aggregation (CA), a unified TCI framework for DL and UL beam indication, and enhancements to the signaling mechanism for the above features to improve latency and efficiency by making more use of dynamic control signaling (as opposed to Radio Resource Control (RRC)). In another example, these enhancements can include identifying and specifying features to facilitate UL beam selection for UEs equipped with multiple panels based on UL beam indications utilizing a unified TCI framework for UL fast panel selection, taking into account UL coverage loss mitigation due to maximum allowed exposure (MPE).

In one aspect, support for multiple TRP deployment may be enhanced by targeting both FR1 and FR 2. For example, these enhancements may include identifying and specifying features to improve the reliability and robustness of channels other than the Physical Downlink Shared Channel (PDSCH), i.e., physical downlink control (PDCCH), Physical Uplink Shared Channel (PUSCH), and Physical Uplink Control Channel (PUCCH), using multiple Transmit Receive Points (TRPs) and/or multiple panels (based on the reliability characteristics of release 16). These enhancements may also include identifying and specifying quasi co-location (QCL)/TCI related enhancements to enable inter-cell multi-TRP operation (assuming multi-PDSCH reception based on multi-Downlink Control Information (DCI)). These enhancements may also include evaluating and, if desired, specifying beam management related enhancements for simultaneous multiple TRP transmission with multi-panel reception.

Additionally, these enhancements may include enhancements to support High Speed Train (HST) -Single Frequency Network (SFN) deployment scenarios. This example can include identifying and specifying solutions for QCL hypotheses for demodulation reference signals (DMRS) (e.g., multiple QCL hypotheses for the same DMRS port, targeting DL-only transmission), and/or evaluating and specifying (if benefits over the release 16HST enhanced baseline are demonstrated) QCL/QCL-like relationships (i.e., including applicable types and associated requirements) between DL and UL signals by reusing a unified TCI framework.

In summary, the present disclosure relates to the current problem of L1/L2-based mobility, where SSBs are split between Remote Radio Heads (RRHs). For example, in one aspect, each serving cell may have multiple RRHs that share the same SSB ID space. Each RRH may send a subset of the SSB IDs but have the same Physical Cell Identity (PCI) for the serving cell. Thus, when a UE is handed over between RRHs within the same serving cell, the propagation delay to different RRHs may be different. However, in release 15/16, each serving cell belongs to a single Timing Advance Group (TAG), which has a single TA offset value. Thus, when the UE switches RRHs, the gNB may have to trigger a PDCCH order for UL TA measurements and send an updated TA offset to the UE. This may increase RRH handover latency and overhead.

In one aspect, the presented aspects provide for a UE that may determine to handover from a first RRH to a second RRH. The UE may also identify a TAG for the second RRH, the TAG associated with the TA offset, the first RRH and the second RRH associated with the serving cell. The UE may also switch from the first RRH to the second RRH in accordance with the TAG and the associated TA offset. The UE may also transmit data to the second RRH on the uplink communication channel.

In another implementation, the presented aspects also provide a serving cell having a first RRH and a second RRH. The serving cell may send the first TAG and associated TA offset for the second RRH to the UE on a downlink communication channel. The serving cell may also detect a handover of the UE from the first RRH to the second RRH. The serving cell may also receive data from the second RRH on the uplink communication channel.

In some aspects, the RRHs may be remote radio transceivers connected to the carrier radio control panel via an electrical or wireless interface. More specifically, the RRH may be a physical unit within the base station that contains the RF circuitry of the base station plus an analog-to-digital converter or digital-to-analog converter and up/down converter.

The features described will be given in more detail below with reference to fig. 1-6.

As used in this application, the terms "component," "module," "system," and the like are intended to include a computer-related entity, such as but not limited to hardware, software, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to, the following: a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal). Software shall be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subprograms, software modules, applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or other terminology.

The techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other systems. The terms "system" and "network" may often be used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), and so on. CDMA2000 covers IS-2000, IS-95 and IS-656 standards. IS-2000 releases 0 and A are commonly referred to as CDMA 20001X, 1X, etc. IS-656(TIA-656) IS commonly referred to as CDMA 20001 xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes wideband CDMA (wcdma) and other variants of CDMA. TDMA systems may implement radio technologies such as global system for mobile communications (GSM). The OFDMA system may implement radio technologies such as Ultra Mobile Broadband (UMB), evolved UTRA (E-UTRA), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, flash OFDM (TM), and the like. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and LTE-advanced (LTE-A) are new versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, and GSM are described in documents from an organization entitled "third Generation partnership project" (3 GPP). CDMA2000 and UMB are described in documents from an organization entitled "third generation partnership project 2" (3GPP 2). The techniques described herein may be used for the above-mentioned systems and radio technologies, as well as other systems and radio technologies, including cellular (e.g., LTE) communications over a shared radio frequency spectrum band. However, for purposes of example, the following description describes an LTE/LTE-a system, and LTE terminology is used in much of the description below, but the techniques are applicable to applications other than LTE/LTE-a applications (e.g., to fifth generation (5G) NR networks or other next generation communication systems).

The following description provides examples, but does not limit the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, the described methods may be performed in an order different than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

Various aspects or features will be presented in terms of systems that may include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems may include additional devices, components, modules, etc. and/or may not include all of the devices, components, modules etc. discussed in connection with the figures. Combinations of these methods may also be used.

Fig. 1 is a schematic diagram illustrating an example of a wireless communication system and an access network 100. A wireless communication system, also referred to as a Wireless Wide Area Network (WWAN), may include a base station 102, a UE104, an Evolved Packet Core (EPC)160, and/or a 5G core (5GC) 190. The base station 102, which may also be referred to as a network entity, may include a macro cell (high power cellular base station) and/or a small cell (low power cellular base station). The macro cell may include a base station. Small cells may include femto cells, pico cells, and micro cells. In one example, base station 102 can also include a gNB 180, as further described herein.

In one example, some nodes (such as base station 102/gNB 180) can have a modem 240 and a communication component 242 for supporting TAG based on each SSB subset for cell mobility, as described herein. Although base station 102/gNB 180 is shown with modem 240 and communication component 242, this is an illustrative example, and substantially any node may include modem 240 and communication component 242 for providing the corresponding functionality described herein.

In another example, some nodes of the wireless communication system (such as the UE 104) may have a modem 340 and a communication component 342 for intra-cell or inter-cell mobility based on the TAGs of each SSB subset, as described herein. Although the UE104 is shown with a modem 340 and a communication component 342, this is an illustrative example, and substantially any node or type of node may include the modem 340 and the communication component 342 for providing the corresponding functionality described herein.

For example, the

communication components

242 and 342 may be configured to support inter-cell and/or intra-cell mobility based on the TAGs of each SSB subset. In particular, each SSB or subset of SSBs of a serving cell (e.g., base station 102/gNB 180) may be associated with a TAG. The TA offset for each TAG may be continuously updated regardless of whether the UE104 is served by a corresponding ssb (rrh). Further, if the UE104 is switched to a beam that is quasi co-located (QCL) with the SSB in the new TAG, the UE104 may use the latest TA offset for that TAG for uplink transmissions. Thus, the above may save uplink TA measurements and sending updated TA offsets to the UE 104.

In some aspects, the SSB concept may also be extended to other cell-defined Reference Signals (RSs), including channel state information reference signals (CSI-RSs) or PRSs (positioning RSs). In some aspects related to L1/L2 based mobility via PCI selection, each cell may have a single Physical Cell Identifier (PCI). The DCI/MAC-CE may select which cell(s) or PCI to serve the UE 104. Here, the cell may include a serving cell/PCI, or a non-serving cell/PCI, or both.

In another implementation relating to inter-cell mobility centered at L1/L2, multiple modes of operation may be defined. In a first example, each serving cell may be one PCI and may have multiple physical cell sites (e.g., RRHs). Each RRH may send a different set of SSB IDs but have the same PCI for the serving cell. The DCI/MAC-CE may select which RRH(s) or corresponding SSB to serve the UE104 based on the RSRP of each reported SSB ID. In a second example, each serving cell may be configured with multiple PCIs. Each RRH of a serving cell may use one PCI configured for the serving cell and may send the entire set of SSB IDs. The DCI/MAC-CE may select which RRH(s) or corresponding PCI and/or SSB to serve the UE104 based on the RSRP of each reported SSB ID of each reported PCI. In a third example, each serving cell may have one PCI. The DCI/MAC-CE may select which serving cell(s) or corresponding serving cell ID to serve the UE104 based on the RSRP of each reported SSB ID of each reported PCI. The above-described SSB concept can be extended to other cell-defined RSs, e.g., CSI-RS, PRS (positioning reference signals).

A base station 102 configured for 4G LTE, which may be collectively referred to as evolved Universal Mobile Telecommunications System (UMTS) terrestrial radio access network (E-UTRAN), may interface with the EPC 160 through a backhaul link 132 (e.g., using the S1 interface). A base station 102 configured for a 5G NR (which may be collectively referred to as a next generation RAN (NG-RAN)) may interface with a 5GC 190 through a backhaul link 184. Base station 102 may perform one or more of the following functions, among others: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, Radio Access Network (RAN) sharing, Multimedia Broadcast Multicast Service (MBMS), user and device tracking, RAN Information Management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC 160 or the 5GC 190) through backhaul links 134 (e.g., using the X2 interface). The backhaul links 132, 134, and/or 184 may be wired or wireless.

A base station 102 may communicate wirelessly with one or more UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102 'may have a coverage area 110' that overlaps with the coverage areas 110 of one or more macro base stations 102. A network that includes both small cells and macro cells may be referred to as a heterogeneous network. The heterogeneous network may also include a home evolved node b (enb) (henb), which may provide services to a restricted group, which may be referred to as a Closed Subscriber Group (CSG). The communication link 120 between the base station 102 and the UE104 may include Uplink (UL) (also referred to as reverse link) transmissions from the UE104 to the base station 102 and/or Downlink (DL) (also referred to as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna techniques including spatial multiplexing, beamforming, and/or transmit diversity. The communication link may be through one or more carriers. The base station 102/UE104 may use a spectrum of up to a bandwidth of Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) per carrier allocated in a carrier aggregation of up to a total of yxmhz (e.g., for x component carriers) for transmission in the DL and/or UL directions. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

In another example, certain UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a Physical Sidelink Broadcast Channel (PSBCH), a Physical Sidelink Discovery Channel (PSDCH), a Physical Sidelink Shared Channel (PSSCH), and a Physical Sidelink Control Channel (PSCCH). The D2D communication may be over a variety of wireless D2D communication systems such as, for example, FlashLinQ, WiMedia, bluetooth, ZigBee, Wi-Fi based on IEEE 802.11 standards, LTE, or NR.

The wireless communication system may also include a Wi-Fi Access Point (AP)150 that communicates with a Wi-Fi Station (STA)152 via a communication link 154 in the 5GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152/AP 150 may perform a Clear Channel Assessment (CCA) prior to communicating to determine whether a channel is available.

The small cell 102' may operate in licensed and/or unlicensed spectrum. When operating in unlicensed spectrum, the small cell 102' may employ NR and use the same 5GHz unlicensed spectrum as used by the Wi-Fi AP 150. Small cells 102' employing NR in unlicensed spectrum may improve coverage and/or increase capacity of the access network.

The base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), may include an eNB, a gnnodeb (gNB), or other type of base station. Some base stations, such as the gNB 180, may operate in the traditional below 6GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies to communicate with the UE 104. When gNB 180 operates in mmW or near mmW frequencies, gNB 180 may be referred to as a mmW base station. Extremely High Frequencies (EHF) are part of the RF in the electromagnetic spectrum. The EHF has a range of 30GHz to 300GHz and has a wavelength between 1 millimeter and 10 millimeters. The radio waves in this frequency band may be referred to as millimeter waves. Near mmW can be extended down to a frequency of 3GHz, which has a wavelength of 100 mm. The ultra-high frequency (SHF) band extends between 3GHz and 30GHz, also known as centimeter waves. Communications using the mmW/near mmW radio frequency band have extremely high path loss and short range. The mmW base station 180 may utilize beamforming 182 with the UE104 to compensate for the extremely high path loss and short range. Base station 102 as referenced herein may include a gNB 180.

The EPC 160 may include a Mobility Management Entity (MME)162, other MMEs 164, a serving gateway 166, a Multimedia Broadcast Multicast Service (MBMS) gateway 168, a broadcast multicast service center (BM-SC)170, and a Packet Data Network (PDN) gateway 172. MME 162 may communicate with Home Subscriber Server (HSS) 174. MME 162 is a control node that handles signaling between UE104 and EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transported through the serving gateway 166, which serving gateway 166 is itself connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation as well as other functions. The PDN gateway 172 and BM-SC 170 are connected to IP services 176. IP services 176 may include the internet, intranets, IP Multimedia Subsystem (IMS), PS streaming services, and/or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and may be used to schedule MBMS transmissions. The MBMS gateway 168 may be used to distribute MBMS traffic to base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service and may be responsible for session management (start/stop) and for collecting eMBMS-related charging information.

The 5GC 190 may include an access and mobility management function (AMF)192, other AMFs 193, a Session Management Function (SMF)194, and a User Plane Function (UPF) 195. The AMF 192 may communicate with a Unified Data Management (UDM) 196. The AMF 192 may be a control node that processes signaling between the UE104 and the 5GC 190. In general, the AMF 192 provides QoS flow and session management. User Internet Protocol (IP) packets (e.g., from one or more UEs 104) may be transmitted through the UPF 195. The UPF 195 may provide UE IP address assignment for one or more UEs, as well as other functionality. The UPF 195 is connected to the IP service 197. The IP services 197 may include the internet, intranets, IP Multimedia Subsystem (IMS), PS streaming services, and/or other IP services.

A base station may also be called a gbb, a node B, an evolved node B (enb), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a Basic Service Set (BSS), an Extended Service Set (ESS), a Transmit Receive Point (TRP), or some other suitable terminology. The base station 102 provides an access point for the UE104 to the EPC 160 or 5GC 190. Examples of UEs 104 include cellular phones, smart phones, Session Initiation Protocol (SIP) phones, laptops, Personal Digital Assistants (PDAs), satellite radios, positioning systems (e.g., satellite, terrestrial), multimedia devices, video devices, digital audio players (e.g., MP3 player), cameras, game consoles, tablets, smart devices, robots, drones, industrial/manufacturing devices, wearable devices (e.g., smart watches, smart clothing, smart glasses, virtual reality glasses, smart wristbands, smart jewelry (e.g., smart rings, smart bracelets)), vehicles/vehicle devices, appliances (e.g., parking meters, electricity meters, gas meters, water meters, flow meters), gas pumps, large or small kitchen appliances, medical/healthcare devices, implants, sensors/actuators, wireless communication devices, and/or wireless communication devices, A display or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., meters, pumps, monitors, cameras, industrial/manufacturing devices, appliances, vehicles, robots, drones, etc.). IoT UEs may include MTC/enhanced MTC (eMTC, also known as CAT-M, CAT M1) UEs, NB-IoT (also known as CAT NB1) UEs, and other types of UEs. In this disclosure, eMTC and NB-IoT may refer to future technologies that may evolve from or may be based on these technologies. For example, emtcs may include femmtc (further eMTC), efmtc (further enhanced eMTC), MTC (large-scale MTC), etc., and NB-IoT may include eNB-IoT (enhanced NB-IoT), FeNB-IoT (further enhanced NB-IoT), etc. UE104 may also be referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, or some other suitable terminology.

2-5, aspects are depicted with reference to one or more components and one or more methods that may perform the acts or operations described herein, where aspects of dashed lines may be optional. While the operations described below in fig. 4 and 5 are presented in a particular order and/or performed by example components, it should be appreciated that the actions and the order in which the components perform the actions may vary depending on the implementation. Further, it should be understood that the following acts, functions, and/or described components may be performed by a specifically programmed processor, a processor executing specifically programmed software or a computer readable medium, or by any other combination of hardware components and/or software components capable of performing the described acts or functions.

Referring to fig. 2, one example of an implementation of a node, such as a base station 102 (e.g., base station 102 and/or gNB 180 as described above), may include various components, some of which have been described above and further described herein, including components such as one or more processors 212 and memory 216 and transceiver 202 in communication via one or more buses 244, which may operate in conjunction with a modem 240 and/or a communication component 242 for supporting inter-cell or intra-cell mobility based on TAGs for each subset of SSBs.

In an aspect, the one or more processors 212 may include a modem 240 using one or more modem processors and/or may be part of the modem 240. Thus, various functions associated with the communications component 242 may be included in the modem 240 and/or the processor 212 and, in one aspect, may be performed by a single processor, while in other aspects, different ones of the functions may be performed by a combination of two or more different processors. For example, in one aspect, the one or more processors 212 may include any one or any combination of the following: a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receive processor, or a transceiver processor associated with transceiver 202. In other aspects, some of the features of the one or more processors 212 and/or modem 240 associated with the communication component 242 may be performed by the transceiver 202.

Further, the memory 216 may be configured to store data used herein and/or a local version of the application 275 or the communication component 242 executed by the at least one processor 212 and/or one or more of its subcomponents. The memory 216 may include any type of computer-readable medium usable by the computer or at least one processor 212, such as Random Access Memory (RAM), Read Only Memory (ROM), magnetic tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and any combination thereof. In one aspect, for example, memory 216 may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes for defining communication component 242 and/or one or more of its subcomponents, and/or data associated therewith, when base station 102 is operating at least one processor 212 to execute communication component 242 and/or one or more of its subcomponents.

The transceiver 202 may include at least one receiver 206 and at least one transmitter 208. The receiver 206 may include hardware for receiving data and/or software executable by a processor, the code comprising instructions and being stored in a memory (e.g., a computer-readable medium). Receiver 206 may be, for example, a Radio Frequency (RF) receiver. In an aspect, receiver 206 may receive signals transmitted by at least one base station 102. In addition, receiver 206 may process such received signals and may also obtain measurements of signals such as, but not limited to, Ec/Io, signal-to-noise ratio (SNR), Reference Signal Received Power (RSRP), Received Signal Strength Indicator (RSSI), and so forth. The transmitter 208 may include hardware for transmitting data and/or software executable by a processor, the code comprising instructions and being stored in a memory (e.g., a computer-readable medium). Suitable examples of the transmitter 208 may include, but are not limited to, an RF transmitter.

Further, in an aspect, the base station 102 may include an RF front end 288 that is operable in communication with the one or more antennas 265 and the transceiver 202 to receive and transmit radio transmissions, e.g., wireless communications transmitted by at least one base station 102 or wireless transmissions transmitted by the UE 104. The RF front end 288 may be connected to one or more antennas 265 and may include one or more Low Noise Amplifiers (LNAs) 290, one or more switches 292, one or more Power Amplifiers (PAs) 298, and one or more filters 296 for transmitting and receiving RF signals. The antenna 265 may include one or more antennas, antenna elements, and/or antenna arrays.

In one aspect, LNA290 may amplify the received signal at a desired output level. In one aspect, each LNA290 may have a specified minimum gain value and maximum gain value. In one aspect, the RF front end 288 may use one or more switches 292 to select a particular LNA290 and its specified gain value based on a desired gain value for a particular application.

Further, for example, the RF front end 288 may use one or more PAs 298 to amplify signals for RF output at a desired output power level. In one aspect, each PA 298 may have a specified minimum gain value and maximum gain value. In one aspect, RF front end 288 may use one or more switches 292 to select a particular PA 298 and its specified gain value based on a desired gain value for a particular application.

Further, for example, the RF front end 288 may filter the received signal using one or more filters 296 to obtain an input RF signal. Similarly, in one aspect, for example, the output from a respective PA 298 may be filtered using a respective filter 296 to produce an output signal for transmission. In one aspect, each filter 296 may be connected to a particular LNA290 and/or PA 298. In an aspect, the RF front end 288 may use one or more switches 292 to select a transmit path or a receive path using a specified filter 296, LNA290, and/or PA 298 based on a configuration as specified by the transceiver 202 and/or processor 212.

Thus, the transceiver 202 may be configured to transmit and receive wireless signals through the one or more antennas 265 via the RF front end 288. In an aspect, the transceiver may be tuned to operate at a specified frequency such that the UE104 may communicate with, for example, one or more base stations 102 or one or more cells associated with one or more base stations 102. In an aspect, for example, the modem 240 may configure the transceiver 202 to operate at a specified frequency and power level based on a UE configuration of the UE104 and a communication protocol used by the modem 240.

In one aspect, the modem 240 can be a multi-band, multi-mode modem that can process digital signals and communicate with the transceiver 202 such that digital data is transmitted and received using the transceiver 202. In an aspect, the modem 240 may be multi-band and may be configured to support multiple frequency bands for a particular communication protocol. In one aspect, the modem 240 may be multi-modal and configured to support multiple operating networks and communication protocols. In an aspect, the modem 240 may control one or more components of the UE104 (e.g., the RF front end 288, the transceiver 202) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In one aspect, the modem configuration may be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration may be based on configuration information associated with the UE104 as provided by the network during cell selection and/or cell reselection.

In an aspect, processor 212 may correspond to one or more of the processors described in connection with the UE in fig. 6. Similarly, memory 216 may correspond to the memory described in connection with the UE in fig. 6.

With reference to fig. 3, one example of an implementation of the UE104 may include various components, some of which have been described above and further described herein, including components such as the one or more processors 312 and memory 316 and transceiver 302, which communicate via one or more buses 344, which may operate in conjunction with the modem 340.

The transceiver 302, receiver 306, transmitter 308, one or more processors 312, memory 316, applications 375, bus 344, RF front end 388, LNA 390, switch 392, filter 396, PA 398, and one or more antennas 365 may be the same as or similar to the corresponding components of the base station 102 as described above, but configured or otherwise programmed for base station operation as opposed to base station operation.

In an aspect, processor 312 may correspond to one or more of the processors described in connection with the base station in fig. 6. Similarly, the memory 316 may correspond to the memory described in connection with the base station in fig. 6.

Turning now to fig. 4 and 5, aspects are depicted with reference to one or more components and one or more methods that may perform the acts or operations described herein, wherein the dashed aspects may be optional. While the operations described below in fig. 4 and 5 are presented in a particular order and/or performed by example components, it should be appreciated that the actions and the order in which the components perform the actions may vary depending on the implementation. Further, it should be understood that the following acts, functions, and/or described components may be performed by one or more components with reference to fig. 1, 2, 3, and/or 6, by a specially programmed processor, a processor executing specially programmed software or computer readable media, or by any other combination of hardware components and/or software components capable of performing the described acts or functions, as described herein.

Fig. 4 shows a flow diagram of an example of a method 400 for wireless communication at, for example, a UE. In one example, the UE104 may perform the functions described in the method 400 using one or more of the components described in fig. 1, 3, and 6.

At block 402, the method 400 may determine to switch from a first RRH to a second RRH. In an aspect, communications component 342 (e.g., in conjunction with processor 312, memory 316, and/or transceiver 302) may be configured to determine to switch from a first RRH to a second RRH. Accordingly, the UE104, the processor 312, the communication component 342, or one of its subcomponents may define means for determining to switch from a first RRH to a second RRH. In some aspects, switching from a first RRH to a second RRH at a cell comprises: the beam of the second RRH is used to communicate with the cell instead of the beam of the first RRH.

At block 404, the method 400 may identify a TAG for the second RRH, the TAG associated with the TA offset, the first RRH and the second RRH associated with the serving cell. In an aspect, the communication component 342 (e.g., in conjunction with the processor 312, memory 316, and/or transceiver 302) may be configured to identify a TAG for the second RRH, the TAG associated with the TA offset, the first RRH and the second RRH associated with the serving cell. Accordingly, the UE104, the processor 312, the communication component 342, or one of its subcomponents, may define means for identifying a TAG for the second RRH, the TAG associated with the TA offset, the first RRH and the second RRH associated with the serving cell. In some aspects, the second RRH may be different from the first RRH.

At block 406, the method 400 may switch from the first RRH to the second RRH according to the TAG and associated TA offset. In an aspect, the communication component 342 (e.g., in conjunction with the processor 312, memory 316, and/or transceiver 302) may be configured to switch from a first RRH to a second RRH in accordance with a TAG and an associated TA offset. Accordingly, the UE104, the processor 312, the communication component 342, or one of its subcomponents, may define means for switching from a first RRH to a second RRH in accordance with a TAG and an associated TA offset.

At block 408, the method 400 may transmit data to the second RRH on the uplink communication channel. In an aspect, the communication component 342 (e.g., in conjunction with the processor 312, memory 316, and/or transceiver 302) may be configured to transmit data to the second RRH on an uplink communication channel. Accordingly, the UE104, the processor 312, the communication component 342, or one of its subcomponents, may define a means for transmitting data on the uplink communication channel to the second RRH.

In some aspects, the first RRH may be associated with a different TAG and associated TA offset than the TAG associated with the TA offset of the second RRH.

In some aspects, the first RRH may be associated with a first subset of RSs and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs may be associated with a TAG and the first subset of RSs is associated with a different TAG.

In some aspects, switching from a first RRH to a second RRH may comprise: switching from a first set of beams associated with a first RRH to a second set of beams associated with a second RRH, the second set of beams being quasi-co-located with a second RS subset of TAGs.

In some aspects, the method 400 may comprise: receiving a DCI or MAC CE on a downlink communication channel, the DCI or MAC CE indicating one or both of a first RRH or a second RRH to serve a UE.

In some aspects, the method 400 may comprise: performing uplink TA measurements for both the first RRH and the second RRH; and updating the TAG and TA offset of the second RRH and a different TAG and TA offset of the first RRH.

In some aspects, the TAG for the second RRH may correspond to the most recently received TAG for the second RRH.

In some aspects, the data may be sent on the uplink communication channel based on the most recently received TAG for the second RRH.

In some aspects, the RS may correspond to at least one of an SSB reference signal, a channel state information reference signal, or a positioning reference signal.

In some aspects, the method 400 may comprise: receiving a DCI or MAC CE indicating one or both of a plurality of cells or a plurality of PCIs associated with one or both of a serving cell or a non-serving cell.

Fig. 5 shows a flow diagram of an example of a method 500 for wireless communication, e.g., at a network entity. In one example, base station 102 may perform the functions described in method 500 using one or more of the components described in fig. 1, 2, and 6.

At block 502, the method 500 may send a first TAG and associated TA offset for a second RRH to the UE on a downlink communication channel. In an aspect, the communication component 242 (e.g., in conjunction with the processor 212, memory 216, and/or transceiver 202) may be configured to transmit the first TAG and associated TA offset for the second RRH to the UE on a downlink communication channel. Accordingly, the base station 102, the processor 212, the communication component 242, or one of its subcomponents, may define means for transmitting the first TAG and associated TA offset for the second RRH to the UE on a downlink communication channel.

At block 504, the method 500 may detect a handover of the UE from a first RRH to a second RRH. In an aspect, communications component 242 (e.g., in conjunction with processor 212, memory 216, and/or transceiver 202) may be configured to detect a handover of a UE from a first RRH to a second RRH. Accordingly, the base station 102, the processor 212, the communication component 242, or one of its subcomponents may define means for detecting a handover of a UE from a first RRH to a second RRH.

At block 506, the method 500 may receive data from the second RRH on the uplink communication channel. In an aspect, the communication component 242 (e.g., in conjunction with the processor 212, the memory 216, and/or the transceiver 202) may be configured to receive data from the second RRH over an uplink communication channel. Accordingly, the base station 102, the processor 212, the communication component 242, or one of its subcomponents, may define a means for receiving data from the second RRH on the uplink communication channel.

In some aspects, the method 500 may include: sending a second TAG and associated TA offset for a second RRH to the UE after transmission of the first TAG.

In some aspects, detecting a handover from a first RRH to a second RRH may comprise: detecting a handoff based on a second TAG for a second RRH and an associated TA offset, the second TAG and associated TA offset corresponding to a nearest TAG.

In some aspects, a first RRH can be associated with a first subset of RSs and a second RRH can be associated with a second subset of RSs, and wherein the second subset of RSs is associated with a TAG and the first subset of RSs is associated with a different TAG.

In some aspects, the method 500 may include: transmitting a DCI or MAC CE on a downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

In some aspects, the method 500 may include: transmitting a DCI or MAC CE indicating one or both of a plurality of cells or a plurality of PCIs, the plurality of cells or the plurality of PCIs being associated with one or both of a serving cell or a non-serving cell.

Fig. 6 is a block diagram of a MIMO communication system 680 that includes a base station 102 and a UE 104. The MIMO communication system 600 may illustrate aspects of the wireless communication access network 100 described with reference to fig. 1. The base station 102 may be an example of aspects of the base station 102 described with reference to fig. 1. The base station 102 may be equipped with

antennas

634 and 635 and the UE104 may be equipped with

antennas

652 and 653. In MIMO communication system 600, base station 102 may be capable of transmitting data on multiple communication links simultaneously. Each communication link may be referred to as a "layer," and the "rank" of a communication link may indicate the number of layers used for communication. For example, in a 2x2 MIMO communication system where the base station 102 transmits two "layers," the rank of the communication link between the base station 102 and the UE104 is 2.

At the base station 102, a transmit (Tx) processor 620 may receive data from a data source. Transmit processor 620 may process the data. Transmit processor 620 may also generate control symbols or reference symbols. Transmit MIMO processor 630 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, or the reference symbols, if applicable, and may provide output symbol streams to transmit modulators/

demodulators

632 and 633. Each modulator/demodulator 632 through 633 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator/demodulator 632 through 633 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a DL signal. In one example, DL signals from modulators/

demodulators

632 and 633 can be transmitted via

antennas

634 and 635, respectively.

The UE104 may be an example of aspects of the UE104 described with reference to fig. 1 and 2. At the UE104,

UE antennas

652 and 653 may receive DL signals from the base station 102 and may provide the received signals to modulators/

demodulators

654 and 655, respectively. Each modulator/demodulator 654-655 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each modulator/demodulator 654-655 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 656 may obtain received symbols from modulators/

demodulators

654 and 655, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive (Rx) processor 658 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE104 to a data output, and provide decoded control information to a processor 680 or a memory 682.

In some cases, processor 680 can execute stored instructions to instantiate communication component 242 (see, e.g., fig. 1 and 2).

On the Uplink (UL), at the UE104, a transmit processor 864 may receive and process data from a data source. Transmit processor 864 may also generate reference symbols for a reference signal. The symbols from transmit processor 864 may be precoded by a transmit MIMO processor 666 (if applicable), further processed by modulators/demodulators 654 and 655 (e.g., for SC-FDMA, etc.), and transmitted to base station 102 based on the communication parameters received from base station 102. At the base station 102, the UL signals from the UE104 may be received by

antennas

634 and 635, processed by modulators/

demodulators

632 and 633, detected by a MIMO detector 636 (if applicable), and further processed by a receive processor 638. The receive processor 638 may provide the decoded data to a data output and to the processor 640 or memory 642.

The components of the UE104 may be implemented, individually or collectively, with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the mentioned modules may be a unit for performing one or more functions related to the operation of MIMO communication system 600. Similarly, the components of the base station 102 may be implemented, individually or collectively, with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the referenced components may be a unit for performing one or more functions related to the operation of MIMO communication system 600.

Some additional examples

Aspects described herein additionally include one or more of the following implementation examples described in the following numbered clauses.

1. A method of wireless communication at a User Equipment (UE), comprising:

identifying a Timing Advance Group (TAG) for a second Remote Radio Head (RRH) different from the first RRH, the TAG associated with a Timing Advance (TA) offset, wherein the first RRH and the second RRH are associated with a serving cell;

switching from the first RRH to the second RRH in accordance with the TAG and associated TA offset; and

transmitting data to the second RRH on an uplink communication channel.

2. The method of clause 1, wherein the first RRH is associated with a different TAG and associated TA offset, the different TAG being different from the TAG associated with the TA offset of the second RRH.

3. The method of any preceding clause, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the TAG and the first subset of RSs is associated with a different TAG.

4. The method of any preceding clause, wherein switching from the first RRH to the second RRH comprises:

switching from a first set of beams associated with the first RRH to a second set of beams associated with the second RRH, wherein the second set of beams is quasi-co-located with the second RS subset of the TAG.

5. The method of any preceding clause, further comprising: receiving Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE) on a downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

6. The method of any preceding clause, further comprising:

performing uplink TA measurements for both the first RRH and the second RRH; and

updating the TAG and TA offset of the second RRH and the different TAG and TA offset of the first RRH.

7. The method of any preceding clause, wherein the TAG for the second RRH corresponds to a most recently received TAG for the second RRH.

8. The method of any preceding clause, wherein the data is transmitted on the uplink communication channel based on the most recently received TAG for the second RRH.

9. The method of any preceding clause, wherein the first and second subsets of RSs correspond to at least one of Synchronization Signal Block (SSB) reference signals, channel state information reference signals, or positioning reference signals.

10. The method of any preceding clause, further comprising: receiving Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE), the DCI or MAC CE indicating one or both of a plurality of cells or a plurality of Physical Cell Identifiers (PCIs), wherein the plurality of cells or the plurality of PCIs are associated with one or both of a serving cell or a non-serving cell.

11. A method of wireless communication at a serving cell having a first Remote Radio Head (RRH) and a second RRH, comprising:

transmitting a first Timing Advance Group (TAG) and an associated Timing Advance (TA) offset for the second RRH to a User Equipment (UE) on a downlink communication channel;

detecting a handover of the UE from the first RRH to the second RRH; and

receiving data from the second RRH on an uplink communication channel.

12. The method of clause 11, further comprising: sending a second TAG and associated TA offset for the second RRH to the UE after transmission of the first TAG.

13. The method of any preceding clause, wherein detecting the handover from the first RRH to the second RRH comprises: detecting the handover as a function of the second TAG and associated TA offset for the second RRH, the second TAG and associated TA offset corresponding to a nearest TAG.

14. The method of any preceding clause, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the first TAG and the first subset of RSs is associated with the second TAG.

15. The method of any preceding clause, wherein the first and second subsets of RSs correspond to at least one of SSB reference signals, channel state information reference signals, or positioning reference signals.

16. The method of any preceding clause, further comprising: transmitting Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE) on the downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

17. The method of any preceding clause, further comprising: transmitting Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE), the DCI or MAC CE indicating one or both of a plurality of cells or a plurality of Physical Cell Identifiers (PCIs), wherein the plurality of cells or the plurality of PCIs are associated with one or both of a serving cell or a non-serving cell.

18. An apparatus for wireless communication, comprising:

a transceiver;

a memory configured to store instructions; and

at least one processor communicatively coupled with the transceiver and the memory, wherein the at least one processor is configured to:

transmitting data to the second RRH on an uplink communication channel.

19. The apparatus of clause 18, wherein the first RRH is associated with a different TAG and associated TA offset, the different TAG being different from the TAG associated with the TA offset of the second RRH.

20. The apparatus of any preceding clause, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the TAG and the first subset of RSs is associated with a different TAG.

21. The apparatus of any preceding clause, wherein to switch from the first RRH to the second RRH, the at least one processor is further configured to:

22. The apparatus of any preceding clause, wherein the at least one processor is further configured to: receiving Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE) on a downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

23. The apparatus of any preceding clause, wherein the at least one processor is further configured to:

24. The apparatus of any preceding clause, wherein the TAG for the second RRH corresponds to a most recently received TAG for the second RRH, and wherein the data is transmitted on the uplink communication channel based on the most recently received TAG for the second RRH.

25. The apparatus of any preceding clause, wherein the first and second subsets of RSs correspond to at least one of Synchronization Signal Block (SSB) reference signals, channel state information reference signals, or positioning reference signals.

26. An apparatus for wireless communication having a first Remote Radio Head (RRH) and a second RRH, comprising:

a transceiver;

a memory configured to store instructions; and

detecting a handover of the UE from the first RRH to the second RRH; and

receiving data from the second RRH on an uplink communication channel.

27. The apparatus of clause 26, wherein the at least one processor is further configured to: sending a second TAG and associated TA offset for the second RRH to the UE after transmission of the first TAG.

28. The apparatus of any preceding clause, wherein to detect the handover from the first RRH to the second RRH, the at least one processor is further configured to: detecting the handover as a function of the second TAG and associated TA offset for the second RRH, the second TAG and associated TA offset corresponding to a nearest TAG.

29. The apparatus of any preceding clause, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the first TAG and the first subset of RSs is associated with the second TAG.

30. The apparatus of any preceding clause, wherein the first and second subsets of RSs correspond to at least one of SSB reference signals, channel state information reference signals, or positioning reference signals.

The above detailed description, set forth above in connection with the appended drawings, describes examples and is not intended to represent the only examples that may be implemented or within the scope of the claims. The term "example" when used in this description means "serving as an example, instance, or illustration," and is not "preferred" or "advantageous over other examples. The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, the techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, computer executable code or instructions stored on a computer readable medium, or any combination thereof.

The various illustrative blocks and components described in connection with the present disclosure may be implemented or performed with a specially programmed device designed to perform the functions described herein, such as but not limited to a processor, a Digital Signal Processor (DSP), an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The specially programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A specially programmed processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a non-transitory computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a specially programmed processor, hardware, hard-wired, or a combination of any of these. Features implementing functions may also be physically located at various locations, including being distributed such that some of the functions are implemented at different physical locations. Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise or clear from context, a phrase such as "X employs a or B" is intended to mean any of the natural inclusive permutations. That is, for example, any of the following examples satisfies the phrase "X employs a or B": x is A; x is B; or X employs both A and B. Further, as used herein (including in the claims), or as used in a list of items ending with "at least one of indicates a disjunctive list such that, for example, a list of" A, B or at least one of C "means a, or B, or C, or AB, or AC, or BC, or ABC (a and B and C).

Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Furthermore, although elements of the described aspects and/or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Moreover, all or a portion of any aspect and/or embodiment may be utilized with all or a portion of any other aspect and/or embodiment, unless stated otherwise. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of wireless communication at a User Equipment (UE), comprising:

switching from the first RRH to the second RRH in accordance with the TAG and the associated TA offset; and

transmitting data to the second RRH on an uplink communication channel.

2. The method of claim 1, wherein the first RRH is associated with a different TAG and associated TA offset, the different TAG being different from the TAG associated with the TA offset of the second RRH.

3. The method of claim 2, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the TAG and the first subset of RSs is associated with the different TAG.

4. The method of claim 3, wherein switching from the first RRH to the second RRH comprises:

5. The method of claim 2, further comprising: receiving Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE) on a downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

6. The method of claim 5, further comprising:

7. The method of claim 6, wherein the TAG for the second RRH corresponds to a most recently received TAG for the second RRH.

8. The method of claim 7, wherein the data is transmitted on the uplink communication channel based on the most recently received TAG for the second RRH.

9. The method of claim 3, wherein the first and second subsets of RSs correspond to at least one of Synchronization Signal Block (SSB) reference signals, channel state information reference signals, or positioning reference signals.

10. The method of claim 1, further comprising: receiving Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE), the DCI or MAC CE indicating one or both of a plurality of cells or a plurality of Physical Cell Identifiers (PCIs), wherein the plurality of cells or the plurality of PCIs are associated with one or both of a serving cell or a non-serving cell.

detecting a handover of the UE from the first RRH to the second RRH; and

receiving data from the second RRH on an uplink communication channel.

12. The method of claim 11, further comprising: sending a second TAG and associated TA offset for the second RRH to the UE after transmission of the first TAG.

13. The method of claim 12, wherein detecting the handover from the first RRH to the second RRH comprises: detecting the handover as a function of the second TAG and associated TA offset for the second RRH, the second TAG and associated TA offset corresponding to a nearest TAG.

14. The method of claim 12, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the first TAG and the first subset of RSs is associated with the second TAG.

15. The method of claim 14, wherein the first and second subsets of RSs correspond to at least one of SSB reference signals, channel state information reference signals, or positioning reference signals.

16. The method of claim 11, further comprising: transmitting Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE) on the downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

17. The method of claim 11, further comprising: transmitting Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE), the DCI or MAC CE indicating one or both of a plurality of cells or a plurality of Physical Cell Identifiers (PCIs), wherein the plurality of cells or the plurality of PCIs are associated with one or both of a serving cell or a non-serving cell.

18. An apparatus for wireless communication, comprising:

a transceiver;

a memory configured to store instructions; and

transmitting data to the second RRH on an uplink communication channel.

19. The apparatus of claim 18, wherein the first RRH is associated with a different TAG and associated TA offset, the different TAG being different from the TAG associated with the TA offset of the second RRH.

20. The apparatus of claim 19, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the TAG and the first subset of RSs is associated with the different TAG.

21. The apparatus of claim 20, wherein to switch from the first RRH to the second RRH, the at least one processor is further configured to:

22. The apparatus of claim 19, wherein the at least one processor is further configured to: receiving Downlink Control Information (DCI) or a Medium Access Control (MAC) Control Element (CE) on a downlink communication channel, the DCI or MAC CE indicating one or both of the first RRH or the second RRH to serve the UE.

23. The apparatus of claim 22, wherein the at least one processor is further configured to:

24. The apparatus of claim 23, wherein the TAG for the second RRH corresponds to a most recently received TAG for the second RRH, and wherein the data is transmitted on the uplink communication channel based on the most recently received TAG for the second RRH.

25. The apparatus of claim 19, wherein the first and second subsets of RSs correspond to at least one of Synchronization Signal Block (SSB) reference signals, channel state information reference signals, or positioning reference signals.

a transceiver;

a memory configured to store instructions; and

detecting a handover of the UE from the first RRH to the second RRH; and

receiving data from the second RRH on an uplink communication channel.

27. The apparatus of claim 26, wherein the at least one processor is further configured to: sending a second TAG and associated TA offset for the second RRH to the UE after transmission of the first TAG.

28. The apparatus of claim 27, wherein to detect the handover from the first RRH to the second RRH, the at least one processor is further configured to: detecting the handover as a function of the second TAG and associated TA offset for the second RRH, the second TAG and associated TA offset corresponding to a nearest TAG.

29. The apparatus of claim 27, wherein the first RRH is associated with a first subset of Reference Signals (RSs) and the second RRH is associated with a second subset of RSs, and wherein the second subset of RSs is associated with the first TAG and the first subset of RSs is associated with the second TAG.

30. The apparatus of claim 29, wherein the first and second subsets of RSs correspond to at least one of SSB reference signals, channel state information reference signals, or positioning reference signals.